The present invention generally relates to a facsimile transmission control method, and more particularly to a facsimile transmission control method suitable for transmitting a document image from a transmitting station to a receiving station having a two-sided printing capability.
Japanese Laid-Open Patent Publication No.2-193156 discloses a proposed facsimile machine which has a two-sided printing capability. In a recent facsimile machine, a reading unit can automatically read a document image on both front and back sides of paper by using a two-sided document reading capability, and transmits the document image to a receiving station in a manner that a front-side image and a back-side image are alternately transmitted.
The proposed facsimile machine, disclosed in the above mentioned publication, receives a document image from a transmitting station by using the two-sided printing capability, in order for saving recording sheets. In the proposed facsimile machine, the received images are printed alternately on the front side of paper and on the back side according to the sequence of receiving of the images.
Hereinafter, the one-side document reading capability refers to a capability to read a document image on the front side of paper, and the two-sided document reading capability refers to a capability to read document images on both the front side and back side of paper. In addition, hereinafter, the two-sided printing capability refers to a capability to print images on both the front side of paper and the back side one side at a time in the sequence of receiving of the images.
In the above described facsimile machine, however, it is impossible to transmit a document image read at a transmitting facsimile station by the one-side document reading capability to a receiving facsimile station with the two-sided printing capability.
Generally, in a G3 facsimile machine, image information is optically read from a document in the forward direction (from the top of the document to the bottom), and it is transmitted in the forward direction for every page in a manner such that the top end image data is first and the bottom end image data is last. On the other hand, in a conventional facsimile machine with the two-sided printing capability, an image of the front side page is printed in the forward direction and an image of the back side page is printed in the backward direction. Thus, it is necessary for a receiving facsimile station to reverse the direction of printing an image of the back side page (received in the forward direction) prior to the printing, so that an image of the front side page is printed in the non-reversed forward direction and alternately an image of the back side page is printed in the reversed direction.
In a conventional facsimile machine with the two-sided document transmitting capability, when a two-sided document image is transmitted, it is necessary to reverse the direction of transmitting a processed image of the back side page (what is first processed is last out and what is last processed is first out). A processed image of the front side page is transmitted in the forward direction and no reversing procedure is performed. Thus, images of all the pages read from the document image are transmitted in the forward direction.
Therefore, when a two-sided document image is transmitted, the reversing procedures for images of the back side pages are repeatedly performed at a transmitting station before transmission and at a receiving station after transmission. Thus, the transmission cost will be unnecessarily increased.
In order to resolve the above described problem, a facsimile transmission method has been proposed by the inventor of the present invention (see Japanese Patent Application No. 4-44508). In the proposed facsimile transmission method, it is detected whether the transmitting station has the two-sided document transmitting capability, and it is detected whether the receiving station has the two-sided printing capability. When it is detected that both the transmitting and receiving stations have the two-sided capabilities mentioned above, a two-sided document image is transmitted by the transmitting station and printed by the receiving station, and no reversing procedures for images of the back side pages are performed, thereby reducing the transmission cost.
However, the proposed facsimile transmission method functions effectively only when the transmitting station and the receiving station have the two-sided capabilities mentioned above. The proposed facsimile transmission method cannot be applied to a facsimile machine which has the one-side document reading capability with no two-sided capability. Facsimile machines with the one-side document reading capability are less expensive and more widely prevailing than facsimile machines with the two-sided printing capability.